Flexible Single-Substrate Integrated Active-Matrix Pyroelectric Sensor

Recently developed flexible active matrix sensors employ organic and large area electronics to enable artificial sensing skin applications. In the proof-of-concept presented here, an active matrix proximity sensor-array is formed by monolithic integration of screen-printed sensors with organic transistors on a single sheet of a polymer film, using only seven industrially scalable patterning steps. A ferroelectric co-polymer of polyvinylidendifluoride (PVDF) serves as the pyro-sensor material, and bottom-gate top-contact organic thin film transistors switch the sensors during operation. An on/off ratio well above 103 and a low off-current below 8 × 10−11 A of the organic transistors result in a dynamic range of 44 dB and allow to detect a human hand approaching to a distance of 20 cm with a signal-to-noise ratio of 28 dB. A basic matrix operation is demonstrated by the correct tracking of a moving human hand.